Decimal to Hex Converter

Type one or more decimal (base-10) numbers and instantly get their hexadecimal equivalents, ready to paste into code, a color picker or a memory tool.

What is the Decimal to Hex Converter?

The Decimal to Hex Converter turns everyday base-10 numbers into hexadecimal (base-16) notation — the format used for color codes, memory addresses, byte values and many low-level programming tasks. Negative numbers are supported too, shown with a leading minus sign in front of the hex digits of their absolute value.

How It Works

Each number you enter is validated as a whole number, converted internally to a big integer, and rendered in base 16 using uppercase letters A-F for digits 10 through 15. Because the conversion is done with arbitrary-precision arithmetic rather than fixed-width numbers, it stays accurate for values well beyond what a standard calculator can represent exactly.

Real-World Use Case

Designers picking an RGB color often start with decimal values from a color-picker tool (say, 42, 63, 75) and need the hex triplet 2A3F4B for CSS — converting each channel here is faster than doing the base conversion by hand.

Frequently Asked Questions

Does it add the 0x prefix automatically?

No, the output is the raw hex digits only, like 2A3F, so you can prepend 0x, #, or any other notation your context needs without having to strip anything first.

Can I convert a batch of numbers at once?

Yes. Put each decimal number on its own line, or separate them with spaces, and every value converts in the same order they were entered.

Why are the hex letters uppercase?

Uppercase A-F is the more common convention for hand-typed hex and matches the styling most editors and hardware datasheets use, though lowercase hex means exactly the same value if your tool expects that instead.

If you're starting from a hex value instead, the reverse converter runs the same conversion the other way. Looking for the reverse? Try the Hex to Decimal Converter →